1. Field of the Invention
The present invention relates to a method of and an apparatus for automatically removing resinous materials adhering to and hardened at an injection head used to pour a liquid reactive resin into a mold assembly.
2. Description of the Related Art
As an interior member for forming a vehicle body, there has heretofore been used a resin molding integrally formed by a covering sheet with an embossed pattern applied thereon and a foaming resin.
In this case, a resin feed mechanism is used to produce the resin molding. The resin feed mechanism has an injection head held in front of an injection hole used for pouring a molten resin into a cavity defined in a mold assembly. Molten reactive resins (stock solution) such as polyol, isocyanate, etc. are mixed together to produce a mixture, which is, in turn, poured into the cavity from the injection head. Then, the mixture is hardened in the cavity to produce a hardened resin. Thereafter, a covering sheet disposed in the mold assembly in advance and the produced hardened resin are integrally formed to produce a desired molded product.
The injection head is fitted in the injection hole to close or block its opening until the reactive resin is hardened in the cavity. Therefore, the reactive resin partly adheres to the leading end of the injection head. Alternatively, the reactive resin adheres to the leading end of the injection head due to the drooling of the reactive resin. It is thus necessary to remove the resinous materials adhering to the leading end of the injection head in order to carry out the next molding process.
As has been disclosed in Japanese Utility Model Application Laid-Open No. 64-57019, for example, there has therefore been proposed an apparatus of a type wherein a resilient coil spring is disposed in a groove defined in the vicinity of a molten-resin injection hole defined in a mold assembly, and blades mounted on the leading end of the coil spring are vertically displaced to be held at a right angle to a resin injection passage by a resilient force of the coil spring upon opening of the mold assembly to enable the cutoff of the resin injection passage, thereby making it possible to cut or scrape off the resinous materials such as the reactive resin adhering to the injection hole.
In the above disclosure, it is, however, necessary to mount the blades on the coil spring which extends and shrinks each time the mold assembly is closed. Therefore, the disclosure has the problem that preparations for mounting the blades on the coil spring are considerably cumbersome and the entire work cannot efficiently and automatically be carried out. Further, since the resinous materials adhering to the injection hole are cut by the blades using the resilient force of the coil spring, the direction in which the coil spring extends is not constant, thereby causing the problem that the blades are positionally displaced and the leading end of the injection head is damaged by cutting or scraping action as the case may be.